The work to be conducted on this grant will be directed towards defining the role of surface immunoglobulins on lymphocyte membranes in the immune response. We will be attempting to separate lymphocytes which contain immunoglobulins on their surface from lymphocytes which do not by immunoabsorbent columns and testing the biologic activity of the separated cells, i.e., their capacity to mount a delayed hypersensitivity reaction or to make humoral antibody. We will also be attempting to purify and isolate lymphocyte plasma membranes and characterize the immunoglobulin associated with these membranes with regard to chemical linkage and to characterize the other components of the plasma membrane with regard to carbohydrate, lipid and protein composition.